﻿using System.Collections.Generic;
using System.Xml.Serialization;
using System.Runtime.Serialization;
using System;

/// <summary>
/// http://weblogs.asp.net/pwelter34/archive/2006/05/03/444961.aspx
/// </summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TValue"></typeparam>
namespace K3R.Generics {
	[XmlRoot("dictionary")]
	public class XmlSerializableDictionary<TKey, TValue>
		: Dictionary<TKey, TValue>, IXmlSerializable {

		#region Constructors
		public XmlSerializableDictionary() : base() { }

		public XmlSerializableDictionary(IDictionary<TKey, TValue> dictionary) : base(dictionary) { }

		public XmlSerializableDictionary(IEqualityComparer<TKey> comparer) : base(comparer) { }

		public XmlSerializableDictionary(int capacity) : base(capacity) { }

		public XmlSerializableDictionary(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey> comparer)
			: base(dictionary, comparer) { }

		public XmlSerializableDictionary(int capacity, IEqualityComparer<TKey> comparer) : base(capacity, comparer) { }

		protected XmlSerializableDictionary(SerializationInfo info, StreamingContext context) : base(info, context) { }
		#endregion

		#region IXmlSerializable Members
		public System.Xml.Schema.XmlSchema GetSchema() {
			return null;
		}

		public void ReadXml(System.Xml.XmlReader reader) {
			XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
			XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue));

			bool wasEmpty = reader.IsEmptyElement;
			reader.Read();

			if (wasEmpty)
				return;

			while (reader.NodeType != System.Xml.XmlNodeType.EndElement) {
				reader.ReadStartElement("item");

				reader.ReadStartElement("key");
				TKey key = (TKey)keySerializer.Deserialize(reader);
				reader.ReadEndElement();

				reader.ReadStartElement("value");
				TValue value = (TValue)valueSerializer.Deserialize(reader);
				reader.ReadEndElement();

				this.Add(key, value);

				reader.ReadEndElement();
				reader.MoveToContent();
			}
			reader.ReadEndElement();
		}

		public void WriteXml(System.Xml.XmlWriter writer) {
			XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
			XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue));

			foreach (TKey key in this.Keys) {
				writer.WriteStartElement("item");

				writer.WriteStartElement("key");
				keySerializer.Serialize(writer, key);
				writer.WriteEndElement();

				writer.WriteStartElement("value");
				TValue value = this[key];
				valueSerializer.Serialize(writer, value);
				writer.WriteEndElement();

				writer.WriteEndElement();
			}
		}
		#endregion
	}
}